This notebook covers the period October 1875-September 1878. All of the entries are by Charles Batchelor The name of his wife, Rosanna Batchelor, appears occasionally as a witness. The notes and drawings relate to telegraphy, etheric force, the telephone, the phonograph, the tasimeter, the electric pen, and the electric light. Most of the entries pertain to Edison's experiments, but some concern Batchelor's own ideas. The book contains 72 numbered pages.